<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        //同：3  7  4
        //微：1  2
        //宏：5
        const first = () => (new Promise((resolve, reject) => {
            console.log(3);
            let p = new Promise((resolve, reject) => {
                console.log(7);
                setTimeout(() => {
                    console.log(5);
                    resolve(6)
                }, 0)
                resolve(1);
            })
            resolve(2);
            p.then((arg) => {
                console.log(arg);
            })
        }))
        first().then(arg => {
            console.log(arg);;
        })
        console.log(4);
    </script>
</body>

</html>